Leach Field Form and Method of Use

ABSTRACT

A leach field form comprising: a container with an open bottom and an open top, and four exterior walls of a first height, and at least one interior wall; at least one geonet volume with an open bottom and an open top located in the container; at least one granular volume with an open bottom and an open top located in the container; and where any of the at least one geonet volumes is separated from any adjacent granular volume by an interior wall. A method of making a leach field using a leach field form comprising: digging a trench; placing a leach field form in the trench; backfilling the trench, allowing backfill to fill any granular volumes in the form; inserting geonet into geonet volume located in the form; and removing the form from the trench.

CROSS-REFERENCES

This application is a divisional application of U.S. patent applicationSer. No. 11/340,917, filed Jan. 27, 2006, entitled “High Aspect RatioWastewater System”, to David A. Potts, which is a continuation-in-partof U.S. patent application Ser. No. 11/144,968, filed on Jun. 3, 2005,entitled “Low Aspect Ratio Wastewater System”, by David A. Potts, thecontents of both which are incorporated by reference herein in theirentirety. This application claims the benefit of U.S. ProvisionalApplication No. 60/945,398, filed on Jun. 21, 2007, entitled “HighTreatment Efficiency Leach Field and Removable Form for Shaping a LeachField”, by David A. Potts, the entire contents of which are fullyincorporated by reference herein.

TECHNICAL FIELD

The present invention relates to leach fields and aerobic treatment ofwastewater within soil, and more particularly to a high aspect ratiowastewater system and leaching conduit.

BACKGROUND

Known leaching conduits, such as arch shape cross section molded plasticchambers, or stone filled trenches with perforated pipe, used fordomestic and commercial wastewater systems provide interior void space,based on the thinking that a buffer space or flow equalization is thusprovided for variations of inflow of wastewater. The sidewalls ofconduits, where they interface with the surrounding soil, are alsocommonly conceived as providing surface area for percolation ofwastewater, in addition to the bottom surface of the conduit. A familiarcrushed stone filled trench, having a modest (4 inch) diameterperforated pipe running along its length may have about 50% void space.Currently, arch shape cross-section molded plastic leaching chambershave entirely open interiors, open bottoms and sloped and perforatedsidewalls. A common cross section shape for each typical conduit has awidth of about 30 to 36 inches and a height of about 12 to 18 inches.Thus this conduit may have from about 12 inches to about 18 inches ofwater depth at any one time. It has been seen that in these prior artconduits, a biomat will often form on the bottom and sides of theconduit, thereby lessening the effectiveness of the leaching conduits toproperly infiltrate the wastewater into the soil. Drip irrigation linesare usually approximately one half inch in diameter and are typicallyburied 12 to 6 inches below grade.

Leaching conduits are typically covered with 6 to 12 inches or more ofsoil, for several reasons. One is to protect the conduits from damage.Another is to prevent contact of humans and animals with potentiallydeleterious microorganisms associated with the wastewater being treated.Still another is to prevent odors. The dimensions of the conduitsdiscussed in the preceding paragraph would lead to the fact that thebottom surface of the conduits are typically at about 24 inches or morebelow the soil surface.

Generally, it is an aim to have aerobic treatment of the wastewater inthe soil. Current thinking with prior art systems is that there is anair-soil gas interchange, so that oxygen is continuously supplied to thesoil, to enable good microbiological treatment. However, the soil depthsat which prior art conduits operate are disadvantaged in this respect.Since the bottom surface of the conduits are typically about 18 to 24inches below the soil surface, the bottom surfaces of the conduits areoften in an anaerobic condition since the oxygen demand exceeds theoxygen supply. One improvement with such systems is to force airserially through the conduit and soil influence zone which surrounds theconduit, as described in U.S. Pat. No. 6,485,647 to David Potts, issuedon Nov. 26, 2002, and which is incorporated herein by reference in itsentirety.

Therefore, a wastewater system is needed that provides for greateraerobic conditions in leaching conduits, thereby allowing for greaterprocessing of the wastewater prior and during absorption into the soil.

SUMMARY

The disclosed invention relates to a leach field form comprising: acontainer with an open bottom and an open top, and four exterior wallsof a first height, and at least one interior wall; at least one geonetvolume with an open bottom and an open top located in the container; atleast one granular volume with an open bottom and an open top located inthe container; and where any of the at least one geonet volumes isseparated from any adjacent granular volume by an interior wall.

The disclosed invention also relates to a method of making a leach fieldusing a leach field form comprising: digging a trench; placing a leachfield form in the trench; backfilling the trench, allowing backfill tofill any granular volumes in the form; inserting geonet into geonetvolume located in the form; and removing the form from the trench.

The disclosed invention also relates to a leach field form comprising: acontainer with an open bottom and an open top; at least one geonetvolume with an open bottom and an open top located in the container.

The disclosed invention also relates to a leach field form comprising:an open bottomed and open topped container comprising: a first end wall,having a first height; a front wall, having a first height, andadjoining the first end wall, with the top of the front wall and the topof the first end wall being generally coplanar; a rear wall, having afirst height, and adjoining the first end wall, with the top of thefront wall and the top of the rear wall being generally coplanar; aplurality of interior walls having a second height, and the plurality ofinterior walls adjoin the front wall and the rear wall with the tops ofthe interior walls, front wall and rear wall being generally coplanar;and where the interior walls are configured to form at least one volumeof a first width, and at least one volume of a second width, and wherethe first width corresponds to a width of a geonet volume and the secondwidth corresponds to a width of a granular volume.

BRIEF DESCRIPTION OF THE DRAWINGS

The present disclosure will be better understood by those skilled in thepertinent art by referencing the accompanying drawings, where likeelements are numbered alike in the several figures, in which:

FIG. 1 is a cross-sectional view of a disclosed low aspect ratioleaching conduit;

FIG. 2 is a perspective view of a geonet;

FIG. 3 a front view of the geonet from FIG. 2;

FIG. 4 is a front view of another embodiment of the disclosed geonet:

FIG. 5 is a front view of another embodiment of the disclosed geonet;

FIG. 6 is an exploded view of one embodiment of a dosing pipe;

FIG. 7 is a side view of the dosing pipe of FIG. 6;

FIG. 8 is a cross-sectional view of the dosing pipe of FIG. 7;

FIG. 9 is a schematic of a disclosed low aspect ratio wastewatertreatment system;

FIG. 10 is a cross-sectional view of a disclosed alternative to ageonet;

FIG. 11 is another embodiment of the disclosed leaching conduit;

FIG. 12 is another embodiment of the disclosed leaching conduit;

FIG. 13 is a perspective view of a disclosed high aspect conduit;

FIG. 14 is a cross-sectional view of the disclosed high aspect conduitfrom FIG. 13;

FIG. 15 is a cross-sectional view of another embodiment of the disclosedhigh aspect conduit;

FIG. 16 is a perspective view of another embodiment of the disclosedhigh aspect conduit;

FIG. 17 is a top view of the disclosed high aspect conduit from FIG. 16;

FIG. 18 is a cross-sectional view of the high aspect conduit from FIG.16;

FIG. 19 is a top view of another embodiment of the high aspect conduit;

FIG. 20 is a side view of the high aspect conduit from FIG. 19;

FIG. 21 is a perspective view of a high aspect conduit form and cover;

FIG. 22 is a top view of the high aspect conduit form from FIG. 21;

FIG. 23 is a side view of the high aspect conduit form from FIG. 21;

FIG. 24 is a cross-sectional view of another disclosed conduit;

FIG. 25 is a top view of a multiple I embodiment of the disclosed form;

FIG. 26 is a top view of an accordion embodiment of the disclosed form;

FIG. 27 is a top view of a box embodiment of the disclosed form; and

FIG. 28 is a flowchart showing one embodiment of the disclosed method ofusing a leach field form.

DETAILED DESCRIPTION Low Aspect Ratio Conduit

In the present invention, as illustrated by the FIGS. 1 through 12,conduit 20 has a much lower aspect ratio (height divided by width) thanconduits in the prior art. Thus, the bottom of the conduit can bepositioned closer to the surface of the soil. And, it is an option toinstall a leaching system by laying a multiplicity of conduits 20 on thesoil grade and to then cover them with appropriately chosen media and/orsoil. This approach is especially advantageous for leaching system siteshaving shallow depths of native soil, such as those which overlie a highwater table or ledge, and the like. The disclosed conduits may beinstalled in spaced apart rows, or in segments which are spaced apart,all interconnected by suitable distribution lines. In the following, oneconduit segment or length is described.

In one embodiment, shown in FIG. 1, the disclosed conduit 20 comprises aperforated dosing pipe 22 which overlies a low aspect channel 24 all ofwhich lie beneath a soil surface 30. The low aspect channel 24 isapproximately rectangular shaped in this cross-sectional view. The pipe22 distributes the wastewater relatively evenly along the length of thechannel 24. A dosing pipe will typically be of a small diameter, forinstance from about ¾ to about 2 inch in diameter. The pipe has suitablesmall spaced apart openings along its length, which openings may besmaller near its water source and larger farther away. A geotextileshroud 26 drapes over the pipe 22, so it runs downwardly and laterallyoutward, onto the top surface of low aspect channel 24. The shroudextends to the outer edges of the channel 24, to keep soil frominfiltrating vertically down into the voids of the channel 24. Theshroud provides assurance that there will be good water flow path fromthe pipe perforations and underside of the pipe, to the top of thechannel 24. Optionally, some crushed stone, or plastic pieces or othergranular or permeable media, may be placed in the space 28 under theshroud 26, near the pipe 22. With reference to FIG. 1, in oneembodiment, the top of the low aspect channel 24 may be consideredessentially planar, because as shown in the end view of FIG. 1, theshroud width “wS”, that is the width of the base of the vaguelytriangular cross section which comprises the region defined by thesloping surfaces of the shroud 26 is a small fraction of the channelwidth “wC”. Alternatively, the shroud 26 may be a preformed shapepermeable material, such as perforated molded plastic. In anothervariation, the shroud may be impermeable when used with blower systemsand since the preponderance of the top of the channel 24 will bepermeable. If a blower is in fluid communication with the low aspectratio channel, the blower may be configured to intermittently blow airand/or some other gas through the channel 24 in order to assist indrying out the adjacent soil and to prevent biological buildup.Additionally, the blower may be configured to provide oxygen to theconduit and assist in dissipating water into the soil. The blower mayalso be configured to keep the dosing pipe and perforations fromclogging with organic matter. The blower may dissipate water from thesoil such that it prevents freezing around the conduit. The entireconduit can also be made of crushed stone, or plastic pieces or othergranular or permeable media in substitution for the “geonet”. This istrue with both the low aspect channel and high aspect channel describedbelow.

The low aspect channel may have a geonet 40 located within it. Thegeonet 40 may be obtained from various manufacturers, such as, but notlimited to: Enkadrain drainage system product No. 9120 from ColbondInc., P.O. Box 1057, Enka, N.C. 28728; and the several geonets namedGrasspave2, Gravelpave2, Rainstore2, Slopetame2, Draincore2, Surefoot4,Rainstore3 from Invisible Structures, Inc., 1600 Jackson Street, Suite310, Golden, Colo. 80401, and Advanedge® flat pipe from AdvancedDrainage Systems, Inc. 4640 Trueman Boulevard, Hilliard, Ohio 43026.Referring now to FIG. 2, a perspective view of a geonet 40 is shown. Thegeonet 40 is typically comprised of an irregularly coiled stringystructure 44 contained between one or two layers of air-permeablesheeting 48, which layers may feel to the touch like thin felt, andwhich is commonly and generically called geotextile. In one embodiment,the geonet 40 has only one layer and one side of the layer has theirregularly coiled string plastic structure, as shown in FIG. 2 and FIG.3 which is a side view of the geonet 40. The low aspect channel 24,comprising the geonet 40, may have an estimated void volume of about90%.

In one embodiment, the low aspect channel 24 will have a thickness, orheight “h” as shown in FIG. 1, of about ¾ inch. The channel width“w_(c)”, or lateral dimension of the channel 24 may be about 12 to about48 inches, and preferably about 12 to about 40 inches. Optionally,geotextile may be placed at the opposing side of the vertical edges ofthe channel 24, to stop potential ingress of soil. In use, wastewaterintroduced into the low aspect channel 24 will percolate into the soilin the downward direction primarily, to a lesser extent in the sidewaysdirections owing to the small vertical edge dimension, and also in theupward direction, when the conduit is full. Since the top of the conduitis permeable to air, there is good microbiological functioning of theleaching system, since air from the soil between the channel 24 and thesurface can diffuse into the channel 24. If a geonet is used which hasboth a top and a bottom layer of air and water-permeable sheeting 48,such as the geonet 52 shown in FIG. 4, the local portion of the toplayer in vicinity of the pipe 22 may be removed, and the shroud 26 needonly extend laterally a small distance from the pipe 22.

In alternate embodiments, the low aspect channel may be deeper than apreferred geonet material. In that case, one or more geonet mats may belaid on top of the other, such as shown in FIG. 5, where two geonet mats40 are laid on top of one another, with the irregularly coiled stringyplastic structure 44 facing each other. In another embodiment, thegeonet mats may be fabricated with a greater thickness, e.g., about 2inches, about 3 inches or about 6 inches in thickness. In embodimentswith thicker geonet mats, it may be practical to omit the dosing pipeand allow the wastewater to flow through the void space of the mat, froma low aspect channel end or selected injection points.

The aspect ratio of the low aspect channel 24 may be less than about6/30 (6 units of height divided by 30 units of width, or about 0.2),preferably the aspect ratio will less than about 1/10 (1 unit of heightdivided by 10 unites of width, or about 0.1), and more preferably theaspect ratio will about 1/30 (1 unit of height divided by 30 unites ofwidth, or about 0.033) to about 1/36 (1 unit of height divided by 36unites of width, or about 0.028) or less. These ratios reflect only thedimensions of the channel 24, and not the dosing pipe 22. However,inasmuch as the preferred dosing pipe 22 is small in diameter andvertical dimension, the ratios are roughly applicable to the whole ofthe conduit as well.

In other embodiments, the low aspect channel 24 may be much wider thanshown; and, it may comprise a continuous wide layer beneath the soilsurface 30. Spaced channels 24 (also called laterals or branches),following the traditional leach field layout may be utilized in anotherembodiment.

In one embodiment, the perforated pipe 22 will be about 4 to 12 inchesbeneath the surface of the soil 30. Thus, in that embodiment, the bottomof the low aspect channel 24 will be about 5-17 inches deep, dependingon the diameter of pipe 22 (if a pipe 22 is used in the embodiment).Thus, it is feasible in many soil areas to have the conduit wholly inthe generally more permeable A-horizon of the soil. Since mostwastewater will percolate downwardly into the soil beneath the lowaspect channel 24, the wastewater will be better treated than if thebottom of the conduit was deeper. The soil nearer the surface has betterchance of being maintained or restored to aerobic condition by naturaldiffusion processes within the soil. In another embodiment, there willonly be one perforation in the pipe 22 about every 10 to 20 feet.

In another embodiment, pipe 22 may be inside the confines of low aspectchannel 24. Solid distribution pipes with a manifold may be used with orwithout dosing pipes 22 to get relatively even water delivery to thechannel 24. Typically dosing will be carried out with a pump and thusthe pipe 22 need only be of small diameter, as previously indicated.Dosing may also be accomplished with a dosing siphon or an accumulatortank with an actuated valve. In another embodiment, dosing pipe 22 maybe sandwiched between two channels 24, an upper channel and a lowerchannel. In another embodiment, when a dosing pipe is sandwiched betweentwo layers, the top geonet layer may have an impermeable sheeting overit to serve to dissipate the water velocity. In still anotherembodiment, the pipe 22 may be located between 2 approximatelyhorizontally parallel low aspect channels 24.

FIG. 6 shows another embodiment of the perforated dosing pipe 22. Inthis embodiment, the dosing pipe comprises a perforated tube 72,perforations 73 in the tube 72, and a slotted sleeve 76. Theperforations 73 of the tube 72 lay along a length of the pipe that isapproximately equal to the length of the low aspect channel 24, thatlength is referred to as L_(LAC). The sleeve length is alsoapproximately equal to the length of the low aspect channel 24. Inanother embodiment, the slotted sleeve 76 may be relatively shortsegments located adjacent to a perforation on the tube 72. For instance,in an embodiment with one perforation about every 15 feet of tube 72,there may be a sleeve 76 of about 6 inches located adjacent to everyperforation. FIG. 7 shows the sleeve 76 fitted over the tube 72. FIG. 8shows a cross-sectional view through the tube 72 and sleeve 76 throughplane A-A. The dotted arrows show possible paths for the water leavingthe perforations, and traveling between the sleeve and the tube andexiting pipe 22 at the slotted area 80. This configuration of aperforated dosing pipe 22 is advantageous in that water will not sprayout of the perforations and immediately impact the soil surrounding theconduit 20. This prevents erosion of the soil around the conduit 20.Thus, in this configuration, the dosing pipe 22, allows water to bedirected only towards the low aspect channel 24, rather than to thesurrounding soil. In this embodiment, a geotextile shroud 26 may beomitted, and a filler medium such as, but not limited to stone, pebblemay be used to prevent soil from entering the geonet. It should beobvious to one of ordinary skill that the perforations 73, may comprisemultiple perforations located along the length of the tube, or there maybe only one perforation per tube 72, or one perforation 73 per a certainlength of tube 72.

While dosing with a pump is preferred for uniformity of distribution,the pipe 22 may be configured to rely on gravity to distribute thewastewater. In such case a larger pipe, up to about 4 inches indiameter, may be used. In still another embodiment, for either a gravityor a pump system, the pipe 22 may be eliminated, and water may bedelivered directly into one end of the channel 24, or into the middle ofthe channel 24.

The disclosed conduit 20 will provide less interior storage volume, orbuffering void space, than prevalent prior art chambers or prior artstone filled trenches. Therefore, depending on the particular flowhandling requirements, a water handling system may be used. For example,as illustrated by FIG. 9, a flow equalization tank 56 receives dischargefrom a processing vessel 60, such as a septic tank. Sewage flows from adischarge source 64 to the processing vessel 60. The discharge source 64may be, but is not limited to: a residence or a business. Periodically,a dosing device, such as, but not limited to a pump 68 will flow waterfrom the flow equalization tank 56 to the conduit 20 located in thesubsurface leach field. The conduit 20 comprises a dosing pipe 22 and alow aspect channel 24. FIG. 6 shows one embodiment of a wastewaterscheme. In other embodiments, the flow equalization tank 56 may beomitted, and the processing vessel 60 may be used for flow equalization.This may be facilitated through the use of a pump to control levels inthe primary processing tank.

In use, the conduit 20 will be periodically dosed with wastewateraccording to the particular soil's hydraulic conductivity, preferablywith loading rates of about 0.25 to about 3 inch per unit horizontalbottom surface area. Preferably, the time between dosing will about twotimes the time for a dose of water to percolate into the soil. It isconceived that that will better enable the low aspect channel 24 andrecently-saturated soil near the low aspect channel to drain of water,and to refill with gas, which is in good part oxygen containing air,flowing downward through the soil and through the permeable top of theconduit. If air distribution pipes are connected to vents, the foregoingeffect can be enhanced by suitable valving at the inlet end of the pipeor pipes, through the use of check valves on the vent lines, whichvalves will close when water is applied to the conduit. When the waterpercolates into the soil, it allows the check valve or similarfunctioning device to open and provide for the flow of air to replace anequal volume of water.

When using a low aspect channel 24 as described in this patentapplication, the vertical dimension (h) may be about one inch. Aone-inch high low aspect channel will only hold one-inch depth of water.So, the ratio of volume to area is 1 to 1. This low ratio of volume toarea arises from the present invention's low aspect ratio and isadvantageous in that it prevents anaerobic conditions from developingsuch that a biomat layer is formed on the bottom surface of the channel24. Therefore, smaller doses of anaerobic water and organisms enter theinfluence zone. The influence zone is that zone where waste water islargely renovated, or biochemically converted into a moreenvironmentally benign form, prior to re-introduction into the groundwater. This prevention of anaerobic conditions encourages a stable andsustainable aerobic microbial community to be present on a continuingbasis thereby providing for greater treatment of the wastewater. Thisalso results in a greater long term acceptance rate of wastewater at agreater percolation rate.

Thus for any given daily flow of water, the flow must be dosed out tothe channel in an amount that does not overflow the conduit, that is,the amount of water must be no more than the volume containable by theconduit at any one time. For instance, if the conduit has 4 rows of 20foot channels, that are each 1 inch high and 10 inches wide, and theconduit is filled either with a geonet or other medium thereby allowinga void space of about 95%, then the total instant capacity for thatconduit is given by the following:

20 feet (length)×12 inches/foot×1 inch (h)×10 inches (w)×4 rows×95%=9120in³.

Thus, wastewater from the source 64 should be dosed out in increments ofno more than about 9120 in³ at a time, to prevent over-flowing of thechannel 24. If the conduit appears to be overflowing, despite limitingthe increment of water to a proper amount, then this may be anindication that there is a malfunction such as, but not limited to ablockage in the system.

In one embodiment of the disclosed conduit, the height of low aspectchannel is about 3 inches or less, and preferably about 1 inch or less.Correspondingly, the ratio of volume to bottom surface area is about 3to 1 and less, preferably about 1 to 1 and less.

Other plastic products which function similarly to a geonet may be used,so long as there is a substantial void between top and bottom layers.For example, a molded plastic three dimensional grid may be used. FIG.10 shows another alternative. The geonet may be replaced by granularmedia 68, such as crushed stone or pea stone, captured between twolayers of air and water permeable sheeting 48, such as a geotextile. Inanother alternative, polystyrene aggregate incorporated into suitablenetting or blanket may be used. For example, the type of polystyreneaggregate associated with the commercial product EZflow Drainage Systemsmay be used. EZflow drainage systems are manufactured by RING IndustrialGroup, LP, 65 Industrial Park, Oakland, Tenn. 38060. When soilconditions are favorable, and there is not a great risk of upwardlymoving fine grained material from the underlying soil, it might beacceptable to eliminate the bottom geotextile layer in any embodiment ofthe invention. In addition the geonet may be replaced by a granularmedia 68 that is not captured between two layers. The granular media mayinclude, but is not limited to: crushed stone, pea stone, crushed glass,ground rubber, tire chips, and round stone

FIG. 11 shows another embodiment of the disclosed conduit. In thisembodiment, the low aspect channel 24 has a width w_(c). However, thegeonet 40 has a width that is greater than w_(c), such that when thegeonet 40 is placed in the channel 24, two sides 84 of the geonet 40bend up or down along the sides of the channel 24. After the channel 24is dug, and the geonet 40 is placed in the channel, then a perforateddosing pipe 22 may be located on top of the geonet 40, with a geotextileshroud 26 over the pipe 22. Then, soil is filled in to the soil surface30. In this embodiment, the channel 24 is no longer mostly rectangularshaped in cross-section, but is approximately “U” shaped incross-section.

FIG. 12 shows another embodiment of the disclosed conduit. In thisembodiment, the low aspect channel 88 may be curved as shown. An air andwater permeable sheeting 48, such as a geotextile material, may belocated on the boundaries of the channel 88 and around the dosing pipe22. The conduit may have a geonet located within it.

While it is an advantage to be able to put the conduit of the inventionnear the surface 30 and atmospheric oxygen, in some climates freezing ofthe soil and water in the conduit could be a risk. There is the obviouschoice to install the system deeper. Another choice, which also mayinvolve compromise with respect to vertical gas interchange, is to placean insulation layer within the soil, above the conduit. For instance, acellular plastic insulation board can be installed. The board mayinhibit the desired vertical gas interchange, so it may be providedselectively with through holes, to enable soil gas flow. Morepreferably, the insulation will be air permeable media which nonethelessprovides better insulation that soil. For instance, pellets of plasticor perlite may be provided, as well as polystyrene aggregate, mentionedabove. If the conduit is comprised of closed cell aggregate, and not ageonet, then the aggregate itself will provide the conduit withself-insulation, which will inhibit the cooling and freezing, at leastin the bottom portion. A blower can also be utilized to provide forincreased drainage during subfreezing conditions.

A geogrid is typically a product that is used to stabilize soil tovehicle loads, etc and is typically a square mesh that gets buried abovethe strata requiring stabilization. The disclosed low aspect ratioconduit may have a geogrid installed between the conduit and the soilsurface to protect the conduit from wheel loads.

The disclosed leaching system is more likely to have aerobic conditionsdue to its low aspect ratio and its low maximum volume to bottom surfaceratio of the conduit, thus leading to better processing of thewastewater. The disclosed system also provides for wastewater processingnear the soil surface, which provides for greater access to oxygen and agreater likelihood of aerobic conditions for the processing.Furthermore, as septic fill becomes increasingly scarce and moreexpensive, the low aspect ratio leaching conduit minimizes the need andquantity of fill required. Additionally, air may be flowed through theconduit to optimize aerobic conditions.

High Aspect Ratio Conduit

On occasion there may not be enough space to install a low aspect ratiowastewater system as described above. Therefore, this applicationdiscloses a low aspect ratio wastewater system that may be thought of asbeing turned on its side, thereby creating a high aspect ratio conduit,wherein the void space is relatively small, and the top of the conduitis relatively close to the surface 30 ground. Referring to FIG. 13, anembodiment of a high aspect conduit 92 is shown. A perforated dosingpipe 22 is shown under a ground surface 30. The perforations 96 areshown located intermittently on the dosing pipe. The dosing pipe 22 isshown with a cap 100 on one end. An air and water permeable sheeting 48encloses a portion of the perforated dosing pipe 22. The generallyrectangular volume beneath the dosing pipe 22, also enclosed by the airpermeable sheeting 48, contains a geonet 40. The generally rectangularshaped volume 41 is also know as the channel of the conduit 92. That isthe conduit 92 comprises a channel 41 where wastewater flows through,and gas infiltrates into. Additionally, since the conduit 92 has a highaspect ratio, then the channel 41 also has a high aspect ratio. Itshould be noted that wherever in this patent application a geonet isreferenced, that geonet may be replaced by a granular material. Thedosing pipe 22 is configured to deliver fluid via the perforations 96down into the geonet 40.

FIG. 14 shows a cross-sectional view of the conduit 92. The dosing pipe22 is surrounded by an air permeable sheeting 48. Additionally, in thisview, the irregularly coiled stringy structure 44 of the geonet 40 canbe seen under the dosing pipe 22, and surrounded by the air and waterpermeable sheeting 48. The height “h” of the channel 41 is shown in FIG.14, and the width “w” of the conduit is also shown. The aspect ratio isgiven by:

Aspect Ratio=h÷w  Eq. 1

Thus it can be seen that the aspect ratio for this disclosed conduit 92is much higher than the conduit shown in FIG. 1. However, this disclosedconduit 92 will take up less land surface area (acreage) than a lowaspect ratio conduit configured to treat generally the same amount offluid and thus will be useful when surface area is not readilyavailable. In some embodiments, the width of the conduit is about 3inches or less, and more particularly between about 0.5 and 2 incheswide. The height of the conduit is between about 48 inches and about 6inches, and more particularly about 12 to about 40 inches. Thus, in thisdocument a high aspect ratio will be about 96 to about 3, and moreparticularly between about 80 and 6. In other embodiments, the highaspect channels may be “Z” shaped for additional surface area. Thebottom surface area of the conduit is relatively small when compared tothe sides of the conduit. The heavier sludge may settle to the bottom ofthe conduit and leave the sides relatively free of blockages, therebyallowing for a greater infiltration along the side of the conduit ascompared to the bottom of the conduit. Additionally, the sides of theconduit have more oxygen since they are closer to the surface.

FIG. 15 shows a cross-sectional view of a another embodiment of thedisclosed high aspect conduit 104. In this conduit 104 there are aplurality of perforated dosing pipes 22, each wrapped in a air and waterpermeable sheeting 48. Additionally, each dosing pipe has a generallyrectangular volume beneath each dosing pipe 48. Each generallyrectangular volume contains a geonet 40. The irregularly coiled stringystructure 44 that makes up the geonet 40 is shown in this view. Eachgeonet 40 is enclosed in an air and water permeable sheeting 48. Eachdosing pipe 22 is configured to deliver fluid via perforations 96 (notseen in this view) into the geonet 40. FIG. 15 shows three dosing pipes22, however, other embodiments may have as few as 1 dosing pipe and upto as many dosing pipes as practical in a given area of land. The highaspect conduits 92, 104 disclosed in FIG. 14 and FIG. 15 could bealternatively constructed by installing a dosing pipe 22, with a geonet44 wrapped around the pipe 22, in the center of an air and waterpermeable sheeting 48 that is about 2 feet wide and folding the sheetingin half about the pipe. A difference in this alternative is that thecore material would be wrapped around the pipe too. Also, the bottom 93of the high aspect conduits 92 and the bottoms 105 of the high aspectconduits 104 may be constructed without an air and water permeablesheeting 48, that is the bottoms 93, 105 may be open to the surroundingsoil. All the channels 41 can also be made of crushed stone, or plasticpieces or other granular or permeable media in substitution for the“geonet”.

FIG. 16 shows a perspective view of another embodiment of a disclosedhigh aspect conduit 108. In this embodiment, three perforated dosingpipes 116, 120, 124 are shown, however it should be understood thatfewer or more dosing pipes may be used as necessary to properly treat anamount of wastewater. Beneath the center dosing pipe 120, is a generallyrectangular volume 112 of geonet 40. This volume 112 generally extendsand runs along a plane that is collinear to the center dosing pipe 120.A volume of 128 of geonet 40 is located under dosing pipe 116 and ispartially adjacent to the geonet volume 112. The geonet volume 128 maybe thought of as a generally rectangular volume formed into a “U” shape,with the bottom of the “U” 132 being adjacent to the volume 112 ofgeonet. There are a plurality of geonet volumes 128 located under thedosing pipe 116. Similarly, there are plurality of “U” shaped volumes128 of geonet located under the dosing pipe 124, with each volume 128having the bottom of the “U” 132 located adjacent to the geonet volume112. The irregularly coiled stringy structure 44 that make up the geonet40 are not shown in this Figure in order to simplify the Figure forbetter understanding. The dosing pipe 116 is configured to deliver fluidto each of the geonet volumes 128 located beneath it via perforationsconfigured to line up with each geonet volume 128. Similarly the dosingpipe 124 is configured to deliver fluid to each of the geonet volumes128 located beneath it via perforations configured to line up with eachgeonet volume 128. The dosing pipe 120 is configured to deliver fluid tothe geonet volume 112. Additionally, each of the dosing pipes 116, 120,124 are covered with an air and water permeable sheeting (not shown inthis view for ease of understanding), and each of the geonet volumes112, and 128 are enclosed in an air and water permeable sheeting (notshown in this view for ease of understanding). In one embodiment, thewidth (w) of the conduit 108 may be about 3 feet, and length (l) of thechannel may be about 8 feet, and the height (h) of the channel may beabout 1 foot. It should be noted that the figures are not necessarilyproportional or to scale. The conduit may be modified to be up to 5 feetin height (h), 10 feet wide (w), and of unlimited length (l). In anotherembodiment, the dosing pipes 116, 120, 124 may be replaced with a lowaspect ratio conduit 20, comprising a low aspect ratio channel 24, withthe low aspect ratio channel 24 adjacent to each of the “U” shapedgeonet volumes 128. Thus water may be applied to the dosing pipe 22, andthe low aspect ratio channel 24 would provide fluid communication to allthe “U” shaped geonet volumes 128. Additionally, in another embodiment,the “U” shaped volumes may be constructed out of pieces about half aslong, that simply lay adjacent to the geonet 40. The conduit 108comprises channels that are coincident with the “U” shaped volumes 128and rectangular volume 112.

FIG. 17 shows a top view of the high aspect conduit 108 from FIG. 16.The irregularly coiled stringy structures 44 that make up the geonet 40are not shown in this Figure in order to simplify the Figure for betterunderstanding. Additionally, each of the dosing pipes 116, 120, 124 arecovered with an air and water permeable sheeting (not shown in this viewfor ease of understanding), and each of the geonet volumes 112, and 128are enclosed in an air and water permeable sheeting (not shown in thisview for ease of understanding).

FIG. 18 is a front cross-sectional view of the conduit 108 from FIGS. 16and 17, through the plane B-B (shown in FIG. 17). In this view, each ofthe perforated dosing pipes 116, 120, 124 are shown wrapped in an airand water permeable sheeting 48. The generally rectangular volume 112 isshown with the irregularly coiled stringy structure 44 that makes up thegeonet 40. The “U” shaped volumes 128 are shown also with the shown withthe irregularly coiled stringy structure 44 that makes up the geonet 40visible. The volumes 112, 128, are enclosed in an air and waterpermeable sheeting 48.

The wastewater conduits shown in FIGS. 13-18 may be easily installed ifa roll of geonet is used. Geonet is often sold in rolls of varioussizes, from about half a foot in width, and about half an inch inthickness, and up to lengths of about 450 feet or more. Thus, one methodof installing a wastewater conduit as shown in FIG. 13, is to obtain ageonet of about one inch in thickness, and about 1 foot in width, andabout 8 feet in length. The 8 foot geonet is covered in an air permeablesheeting on all sides except for the top of the geonet which will beadjacent to a perforated dosing pipe. An 8 foot in length dosing pipe ofabout 1″ outer diameter may then be attached to the 8 foot geonet bywrapping the pipe with an air permeable sheeting and attaching that airpermeable sheeting to the sheeting around the geonet. A trench may bedug about 8-12 inches deep and 8 feet long and about 2 inches wide. Thedosing pipe and geonet may then be placed in trench and the trenchfilled in with soil, sand, or what ever material is suitable. The dosingpipe may then be coupled to the outflow of wastewater from the residenceor business. Conduits may also be about 12 inches high by about 1 inchwide, with length varying depending on the size of land available. Itshould be noted that “U” shaped volumes may be easily formed by simplybending the geonet into the desired shape.

The dosing pipe 22 may be configured to allow fluid such as waste waterto flow into the geonet in a manner similar to that described in U.S.Pat. No. 6,959,882 issued on Nov. 1, 2005 to David A. Potts and entitled“Watering and aerating soil with a drip line”, wherein instead offlowing the fluid into soil, the fluid is flowed into the geonet. U.S.Pat. No. 6,959,882 is fully incorporated in its entirety by referenceherein.

FIG. 19 is a top view of the disclosed high aspect ratio conduit 136.This high aspect ratio conduit 136 comprises a perforated dosing pipe22, a geonet layer 140 laying below and in fluid communication with thepipe 22. The geonet layer 140 comprises a geonet 40 that is about 4inches in thickness “t”, as shown in FIG. 20. It should be noted that inother embodiments, the geonet layer 140 may be replaced with pea stone,crushed stone, plastic pieces or other granular or permeable media.Laying below the geonet layer 140 are a plurality of geonet volumes 144.Each geonet volume 144 comprises a volume of geonet 40 enclosed in anair and water permeable sheeting 48. Please note that the coiled stringystructures of the geonet 40 are not visible due to the air and waterpermeable sheeting 48. The geonet layer 140 is shown partially cut-awayto reveal the geonet volumes 144 below. The width “w” of each geonetvolume may be about 1 inch. The distance “B” between each geonet volumemay be about 2 inches and up to about 10 feet or more apart. In thisembodiment the dosing pipe may have internal diameter of about 4 inches.The depth “D” of each geonet volume 144 may be about 12 inches, see FIG.20.

FIG. 20 shows a side view of the disclosed high aspect ratio conduit136. The thickness “t” of the geonet layer 140, the depth “D” of eachgeonet volume is shown, the width “w” of each geonet volume, and thedistance “D” between each geonet volume 140 are all shown. Theperforations 30 in the dosing pipe 22 may be generally aligned with thegeonet volumes 144. However in other embodiments, the perforations 30need not be aligned with the geonet volumes 144.

FIG. 21 is a perspective view of a conduit form 148 and conduit formcover 152. The conduit form 148 is configured to help install a highaspect ratio conduit 136 easily and quickly in the ground. With certainsoils, such as cohesive soils, simple trenching equipment may besufficient. The top and bottom 156 of the conduit form 152 are open.FIG. 22 is top view of the form 148, and FIG. 23 is a side view of theform 148. Referring now to FIG. 22, a volume 161 is defined by firstendwall 180, a front wall 220, a rear wall 216, a first interior wall188, an imaginary plane 184 through the an through the top surface ofthe form 148, and an imaginary plane 212 through the bottom of theinterior walls 188, 192, 196, 200, and 204. A volume 162 is defined byinterior wall 192, the front wall 220, the rear wall 216, an interiorwall 196, the imaginary plane 184 through the top surface of the form148, and the imaginary plane 212 through the bottom of the interiorwalls 188, 192, 196, 200, and 204. A volume 163 is defined by interiorwall 200, the front wall 220, the rear wall 216, the interior wall 204,the imaginary plane 184 through the top surface of the form 148, and theimaginary plane 212 through the bottom of the interior walls 188, 192,196, 200, and 204. Volumes 161, 162, 163 are each configured to containa geonet volume 140. A volume 165 is defined by the interior wall 188,the front wall 220, the rear wall 216, the interior wall 192, theimaginary plane 184 through the top surface of the form 148, and animaginary plane 216 through the bottom surface 217 of the form 148. Avolume 166 is defined by the interior wall 196, the front wall 220, therear wall 216, the interior wall 200, the imaginary plane 184 throughthe top surface of the form 148, and the imaginary plane 216 through thebottom surface 217 of the form 148. A volume 167 is defined by theinterior wall 204, the front wall 220, the rear wall 216, and a secondend wall 208, the imaginary plane 184 through the top surface of theform 148, and the imaginary plane 216 through the bottom surface 217 ofthe form 148. The volumes 165, 166, and 167 are configured to hold thesoil or sand or any other suitable granular material that will occupythe volumes between the geonet volumes 140. It should be noted that thegeonet can be substituted with other granular material and placed involume 165, 166 and 167. In one embodiment, the height “D₁” of thevolumes 165, 166 and 167 is greater than the height “D₂” of the volumes161, 162, and 163. The form 148 may have a plurality of lifting members168. The lifting members may be lifting hoops as shown in FIG. 21, orany other lifting mechanism configured to allow one to lift the form 148out of the ground. The volumes 161, 162, and 163 have a width that isgenerally “w”, which is generally the same as the width of each geonetvolume described with respect to FIGS. 19 and 20. Similarly, the volumes165, 166, and 167 have a width that is generally “B, which is generallythe same as the width of the granular material, such as soil or sand,which occupies the volumes between the geonet volumes 144. The volumes165, 166, 167 between the geonet volumes will be referred to herein asgranular volumes. Additional forms and trench shoring devices can beutilized to maintain the integrity of the excavation and to placeadditional sand, soil or media around the form. In other embodiments ofthe disclosed forms, D₁ may be about equal to D₂, and the interior walls188,192,196, 200, 204 may extend to the imaginary plane 216. The formhas a plurality of interior walls, 188, 192, 196, 200, 204, and forexterior walls: the first end wall 180, the front wall 220, the rearwall 216, and the second end wall 208. The form may be used without acover in some instances.

The disclosed may comprise several pieces that are welded or otherwisepermanently attached to each other in order to make one form. However,in another embodiment, the form may comprise several pieces (e.g. thewalls) that may be fitted together using a tongue and groove attachingmeans, or other interlocking mechanisms. In this embodiment, the formscan may be easily transported as a stack of flat walls, and fittedtogether at the job site.

Referring back to FIG. 21, the form cover 152 has openings 172configured to lie directly over the volumes 165, 166 and 167. The formcover 152 also has covered portions 173 configured to lie over thevolumes 161, 162 and 163. Additionally, the form cover 152 has aplurality of lifting members 176. The lifting members may be liftinghoops as shown in FIG. 21, or any other lifting mechanism configured toallow one to lift the form cover 152 off of the form 148.

One method of using the form 148 and cover 152 to make a high aspectratio conduit is as follows: dig a trench in the ground that canaccommodate the form 148 and cover 152, fill the volumes 165, 166, and167 with soil, or sand. Once filled, remove the cover 152, fill theopenings volumes 161, 162 and 163 with a geonet. Finally, remove theform 148. At this point, a geonet layer 140 is placed on top of thegeonet volumes and the sand/soil volumes. Next a perforated dosing pipe22 is laid on top of the geonet layer 140 and covered with a geotextilefabric or other material. In another embodiment the dosing pipe may beplaced so that a portion of the dosing pipe lies within the geonetvolumes and the sand/soil volumes. Then, a layer of soil or sand isplaced over the high aspect ratio conduit. Although three volumes 161,162, 163 and three granular volumes 165, 166, 167 are shown, more orfewer volumes may be used depending on how many geonet volumes 144 andgranular volumes are needed for a particular high aspect ratio conduit.Of course, the form cover 152 will be configured to have openings 172corresponding to the granular volumes. The form cover may alsoincorporate a funnel, hopper, etc. into the device to improveconstruction efficiencies.

FIGS. 25 through 27 show top views of three different form shapes, eachof which has an open top and open bottom. FIG. 25 shows a form 400. Theform 400 is empty in the interior 410, to allow the form to be filledwith the desired aggregate material. Aggregate material may include, butis not limited to: man made granular material, naturally occurringgranular material, and geonet. This form may be referred to a repeating“I” form, due the form appearing to be repeating letter I's standing oneach other (or it may be referred to as repeating sideways U shapes).The interior 410 may be referred to as a geonet volume. The geonetvolume 410 may comprise a central volume 411 with fingers 412 extendinggenerally perpendicularly from the central volume. FIG. 26 shows a form420. The form 420 is also empty in the interior 430, to allow the formto be filled with the desired aggregate material. This form 420 may bereferred to as an accordion shaped form. The interior 430 may bereferred to as a geonet volume. FIG. 27 shows a form 440. The form 440is empty in the interior 450, to allow the form to be filled with thedesired aggregate material. The interior 450 may be referred to as ageonet volume. This form 440 may be referred to as a box shape form. Theforms have a length L. The length L may vary from 4 feet to 10 long insome preferred embodiments. In other uses, the forms may be even longer.The height of the forms (the dimension that goes into the paper thatFIGS. 6-8 are shown on) may vary from 12 inches to about 6 feet tall forsome preferred embodiments. In other uses, the height may be evengreater than 6 feet. These forms 410, 420, 440 may have form covers thatwill cover the interior of each of the forms 410, 420, 440. The formsmay also have a lifting means attached to each of them. The form coverswill allow one to dig a trench, place form with a cover into the trench,backfill the trench, thus surround the form with backfill, but since thecover is on the form, no backfill will enter the interior of the form.Once the trench is backfilled, the cover can be removed, and a geonetcan be inserted into the form interior. Then, the form can be removedfrom the trench.

The disclosed invention allows one to maximize the infiltrative surfacearea of leach fields, without utilizing materials that compromise thehydraulic conductivity of the leaching system. This is accomplished withthe use of a rigid form made of steel, aluminum, plastic, wood, etc.Steel is especially good. After an excavation is dug, a form is placedinto the trench. The native soil or specified sand, etc. is backfilledand compacted to the specified values outside the form. Then the desiredaggregate, typically gravel, crushed stone, tire chips, etc. is placedinside the form. Specially designed funnels and covers can also beutilized as shown in FIG. 21 (showing the cover). Once the form isfilled to the desired level (varying heights equates to differenttreatment capacities, separation from groundwater, etc.) the form ispulled out of the ground, typically using excavation equipment. Incertain cases vibrating or shaking the form is desirable. This can beachieved by simply banging on the side of the form with a hammer or witha mechanical vibrator, such as is used on dump truck bodies. Thisvibration also helps to minimize settling of the materials used inconstruction the leach field lateral line. Once the form is pulled out,a wastewater distribution pipe (such as, but not limited to a perforatedpipe) may placed on top or connected within to the leach field. In somecases multiple forms that interlock with tong and groove type joints areutilized to advance a longer leach field lateral line as is shown in myhigh aspect ration system. In addition to having a form interlock withone or more other forms, the forms may comprise separatable walls thatmay attach via a tongue and groove attaching means in order to make theform. If one form is being used, a shoring board may be utilized toshore up the construction materials from falling, or slumping into theexcavation when the form is pulled out and moved ahead. Forms may alsobe utilized that butt together. Steel is a desirable constructionmaterial for these forms due to the high strength and weight, whichhelps prevent the form from moving when being filled inside and aroundthe perimeter.

Thus, the use of a form allows one to keep different materials separate,as is desirable when constructing a leach field and or trench systems inelevated sand mounds. An example would be a rectangular form to keep adiscrete interface between sand and stone. This is often problematicwhen constructing a system in a select fill (often sand) material. Theform allows trench walls that are at a 90 degree angle, as opposed towalls that match the angle of repose of the sand in which the gravellateral is being constructed.

FIG. 28 shows a flowchart describing one disclosed method of using thedisclosed forms. At act 600 a user or installer digs a trench. At act604, the user places a form in the trench. The form, may have a coverattached during this step, or the cover may be placed on the form afterthe form is in the trench. At act 608, the trench is backfilled,allowing backfill to fill any granular volumes in the form (some formsmay not have granular volumes, see FIGS. 25-27). Because the cover is onthe form, backfill will not enter the geonet volume. At act 612 the formcover is removed. At act 616 geonet is inserted into the geonetvolume(s). Crushed stone, or plastic pieces or other granular orpermeable media may be used as a substitute for geonet. At act 620, theform is removed from the trench, leaving behind the geonet locatedwithin the backfill. At act 624 a distribution pipe is placed over thegeonet and backfill (which is now the leach field).

FIG. 24 shows a cross-sectional view of another embodiment of thedisclosed conduit. In this figure, the high aspect ratio conduit 224comprise a plurality of channels 228, 232, 236. Each channel is agenerally rectangular volume, within which is a geonet 40. Theirregularly coiled stringy structure 44 that makes up the geonet 40 isshown in this view. Each geonet 40 is enclosed in an air and waterpermeable sheeting 48. One or more dosing pipes 22 will be in fluidcommunication with the channels. A low aspect ratio conduit can besubstituted for dosing pipe 22. Additionally, there are a plurality ofpairs of anchors 240, attached to the permeable sheeting on adjacentchannels. Each pair of anchors 240 is attached to a line 244. Theanchors 240 and lines 244 are configured to allow the channels 228, 232,236 to be spaced a predetermined amount in the ground to facilitate thebackfilling of the volumes between adjacent channels 228, 232, 236 withsand, or other backfill. However since the lines 244 are attached toadjacent channels, the channels 228, 232, 236 may be collapsed (i.e. setclose together) for shipping. The anchors 240 may be any suitableattaching device, including but not limited to staples, plastic staples,washers. The lines 244 may be any suitable line, including but notlimited to nylon line, rope, twine, chain link. To install the disclosedconduit 224, the channels 228, 232, 236 are expanded to the maximumseparation distance between them, given the length of the lines 244.Stakes are typically driven into the soil to prevent the conduits frommoving around in the trench and to keep them at the desired distanceapart as determined by the lines 244. Although three channels 228, 232,236 are shown in the embodiment, one of ordinary skill will understandthat this conduit may be modified to have fewer channels, or morechannels, such as 10 or more channels.

In use, the disclosed high aspect ratio channels will be periodicallydosed with wastewater so as to fill conduit and displace gas. As thewastewater drains out of the high aspect ratio channels, air is pulledin “behind” the wastewater. Additionally, the system may be configuredto fully drain the high aspect ratio channels between doses. This helpsmaintain aerobic conditions in the conduit and helps oxidize thesludge/biomat. Prior art devices are designed to provide storage volumefor water in the channels. This storing or water in the conduit resultsin the persistence of anaerobic conditions at the soil interface andsubsequent organic buildup and less favorable conditions for treatment.Thus the current invention may configured to fill about 25 to about 100%of the channel void space per dose and allowing the channel to largelydrain before the next dose. Preferably, the time between dosing willabout two times the time for a dose of water to percolate into the soil.It is conceived that that will better enable the high aspect channel andrecently-saturated soil near the high aspect channel to drain of water,and to refill with gas, which is in good part oxygen containing air,flowing downward through the soil and through the permeable top of theconduit. If air distribution pipes are connected to vents, the foregoingeffect can be enhanced by suitable valving at the inlet end of the pipeor pipes, through the use of check valves on the vent lines, whichvalves will close when water is applied to the conduit. When the waterpercolates into the soil, it allows the check valve or similarfunctioning device to open and provide for the flow of air to replace anequal volume of water. With the high aspect ratio channels, thesidewalls will likely play more of a role in water draining than in thelow aspect ratio conduits. Additionally, a larger water column due tothe geometry of the channels will assist in the infiltration of gasesinto the channels as the water drains out of the channels.

The disclosed high aspect ratio channels will have an infiltration areato storage volume ratio of about 9 or greater. The infiltration area tostorage volume ratio is calculated as follows: for a channel that is 1foot high, 3 inches (0.25 feet) wide, and 10 feet long, the maximumstorage volume of that channel is given by 1 foot×0.25 feet×10 feet,which is 2.5 ft³. The infiltration area is given by adding together thesurface areas of the left and right side of the conduit and the bottomof the conduit. The left side of the conduit is given by: 1 foot×10 feetwhich equals 10 ft². The right side of the conduit is given by: 1foot×10 feet which equals 10 ft². The bottom of the conduit is given by0.25 feet×10 feet which equals 2.5 ft². Adding them together gives 22.5ft². The infiltration area to storage volume ratio is therefore 22.5ft²÷2.5 ft³=9 ft⁻¹. The distal ends of the volumes 128 and the interfaceof the volumes 128 and the volume 112 were ignored because we areomitting surfaces at opposing angles, and parallel surfaces closer thanabout 4 inches apart. The logic for this is that saturated soils canresult in proximity to infiltrative surfaces so close together, and gasmovement in these regions is inhibited, which may lead to less aerobicconditions that desired. The disclosed conduits will have widths greaterthan about ½ inch.

It should be noted that the terms “first”, “second”, and “third”, andthe like may be used herein to modify elements performing similar and/oranalogous functions. These modifiers do not imply a spatial, sequential,or hierarchical order to the modified elements unless specificallystated.

While the disclosure has been described with reference to severalembodiments, it will be understood by those skilled in the art thatvarious changes may be made and equivalents may be substituted forelements thereof without departing from the scope of the disclosure. Inaddition, many modifications may be made to adapt a particular situationor material to the teachings of the disclosure without departing fromthe essential scope thereof. Therefore, it is intended that thedisclosure not be limited to the particular embodiments disclosed as thebest mode contemplated for carrying out this disclosure, but that thedisclosure will include all embodiments falling within the scope of theappended claims.

1. A leach field form comprising: a container with an open bottom and anopen top, and four exterior walls of a first height, and at least oneinterior wall; at least one geonet volume with an open bottom and anopen top located in the container; at least one granular volume with anopen bottom and an open top located in the container; and wherein any ofthe at least one geonet volumes is separated from any adjacent granularvolume by an interior wall.
 2. The leach field form of claim 1, whereinthe at least one interior wall is of a first height.
 3. The leach fieldform of claim 1, wherein the at least one interior is of a secondheight, that is less than the first height.
 4. The leach field form ofclaim 1, further comprising: a removable form cover, the removable formcover comprising: at least one opening; at least one covered portion;the removable form cover configured to sit on the open top of thecontainer with the at least one opening laying directly above the atleast one granular volume, and the at least one covered portion layingdirectly above the at least one geonet portion.
 5. The leach field formof claim 1, further comprising: at least one lifting member attached tothe container.
 6. A method of making a leach field using a leach fieldform comprising: digging a trench; placing a leach field form in thetrench; backfilling the trench, allowing backfill to fill any granularvolumes in the form; inserting geonet into geonet volume located in theform; and removing the form from the trench.
 7. The method of claim 6,further comprising: preventing backfill from filling any geonet volumesin the form by using a form cover; and removing a form cover from theleach field form.
 8. The method of claim 6, wherein the inserting stepmay be performed before the backfilling step.
 9. The method of claim 6,wherein the geonet may be comprised of material selected from the groupconsisting of crushed stone, plastic pieces, granular media, andpermeable media.
 10. The method of claim 6, further comprising: placinga distribution pipe in communication with the backfill and the geonet.11. A leach field form comprising: a container with an open bottom andan open top; at least one geonet volume with an open bottom and an opentop located in the container.
 12. The leach field form of claim 11,wherein the form has a stacked I shape.
 13. The leach field form ofclaim 11, wherein the leach field form has an accordion shape.
 14. Theleach field form of claim 11, wherein the leach field form has a boxshape.
 15. The leach field form of claim 11, further comprising: aremovable form cover, the cover configured to sit on the open top, andcover the at least one geonet volume.
 16. A leach field form comprising:an open bottomed and open topped container comprising: a first end wall,having a first height; a front wall, having a first height, andadjoining the first end wall, with the top of the front wall and the topof the first end wall being generally coplanar; a rear wall, having afirst height, and adjoining the first end wall, with the top of thefront wall and the top of the rear wall being generally coplanar; aplurality of interior walls having a second height, and the plurality ofinterior walls adjoin the front wall and the rear wall with the tops ofthe interior walls, front wall and rear wall being generally coplanar;and wherein the interior walls are configured to form at least onevolume of a first width, and at least one volume of a second width, andwherein the first width corresponds to a width of a geonet volume andthe second width corresponds to a width of a granular volume.
 17. Theleach field form of claim 16, further comprising: a second end wall,having a first height, and adjoining the front wall, with the top of thesecond end wall being generally coplanar to the top of the front walland the top of the rear wall.
 18. The leach field form of claim 16,wherein the second height is less than the first height.
 19. The leachfield form of claim 16, further comprising: a removable cover, theremovable cover comprising: at least one opening; at least one coveredportion; wherein the cover is configured to lie on the top of the openedtopped container with each of the at least one opening laying directlyover each of the at least one volume of a second width, and each of theat least one covered portion laying directly over each of the at leastone volume of a first width.
 20. The leach field form of claim 16,further comprising at least one lifting member attached at least one ofthe following: the first end wall, the front wall, the rear wall, thesecond end wall.
 21. The leach field form of claim 19, wherein the coverfurther comprises: a plurality of panels, wherein each panel is locatedabove and configured to cover a single volume of the first width. 22.The leach field form of claim 21, wherein the cover further comprises: aplurality of openings, wherein each opening is located above andconfigured to leave uncovered a single volume of the second width; andwherein each of the plurality of panels has a downward slope in thedirection of a volume of the second width.
 23. The leach field form of16, where the form is configured to be placed in the ground, and furtherconfigured to have granular material placed in the granular volume ofthe form, and have geonet placed in the geonet volume of the form, andthe form is further configured to be extracted from the ground, leavingthe generally granular volume filled with granular material and thegenerally geonet volume filled with geonet, after the form is extractedfrom the ground.
 24. The leach field form of claim 1, further comprisinga hopper configured to fit the leach field form.